Hoistingxjack



(No Model.)

W. N. BELL.

. HOISTING JACK. No. 383,035. Patented May 15, 1,888.

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` NITED STATES PATENT OFFICE.

VILLIAM N. BELL, OF PITTSBURG, PENNSYLVANIA.

HOISTINGQJACK.

ElECIFICATION forming pari: of Letters Patent No. 383,035, dated May l5, 1888,

Application filed September 9, 1887. Serial No. 249,23.

To all 'whom 'it may concern:

Be it known that I, VILLIAM N. BELL, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Hoisting-Jacks; and I do hereby declare the following' to be a full, clear, and exact description thereof.

My invention relates to an improvement in lifting-jacks; and it consists of a cap and base, each having a horizontal plane and two in clined planes converging toward each other, and each incline is provided with tracks adapted to run in grooves in the rollersjournaled in trucks operated by a shaft having a right and left hand screw, whereby said trucks are caused to travel toward and from each` other upon said inclined plane, thereby causing the cap to be elevated or lowered at the will of the operator by the turning of said shaft.

To enable others skilled in the art with which my invention is most nearly connected to make and use it, I will proceed to describe its construction and operation.

In the accompanying drawings, which form part of my specification, Figure l is a side elevation of my improvement. Fig. 2 is an end view of the same.

My invention has for its object the forma tion of a liftingjack that can be manufactured at greatly reduced cost, can be handled with comparatively little trouble, and takes up but little room. rIhe two sections A B are made of cast metal, having horizontal planes C D and inclined planes E F G H and tracks I, adapted to fit the grooves J made in the rollers K, which are journaled in the trucks L, into which is fitted the screw M, having right and left hand screwthreads, and operated by a lever or by ratchet power.'

(No model.)

Each truck L is provided with a screw threaded hole with which the screw M may engage, and with central bearings, Z, for supporting the rollers K in the middle,as well as bearings at each end of the rollers, Each roller is provided with two grooves, J, and each incline has two guide-tracks, I, one on each side of the central slot,which works over the inida dle portion of the screw M.

The operation is as follows: The right and left hand screw M being tted in the trucks L, the two sections A B are placed with the tracks I resting in the grooves J of the rollers K. Power is then applied to the screw M, and the section A will be caused te travel upward, thereby lifting whatever is placed upon it. By reversing the action of the screw the section A will be lowered, the section B forming a solid base or support.

Having thus described my improvement, what I claim is- A lifting-jack comprising the two similar sections Aand B, each provided with reverselyinclined faces, and with two roller guidetracks, I, upon each of the said faces, the trucks L,provided with the right and left hand screw-threaded holes, the outside roller-spin ble bearings and the middle bearings, Z, the rollers K, journaled in said trucks and provided with grooves J engaging with the said guide-tracks, and the right and left hand threaded screw M for operating the said trucks and forcing the rollers against the inclines, substantially as set forth.

In testimony whereof I have hereunto set my hand this 26th day of April, A. D. 1887.

WM. N. BELL. Witnesses:

A. C. JOHNSTON, C. S. JonNsToN. 

